From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Thomas Lockhart <lockhart(at)alumni(dot)caltech(dot)edu> |
Cc: | Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>, pgsql-hackers(at)postgreSQL(dot)org |
Subject: | Re: [HACKERS] Oops, I seem to have changed UNION's behavior |
Date: | 1999-05-09 17:31:52 |
Message-ID: | 2440.926271112@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Thomas Lockhart <lockhart(at)alumni(dot)caltech(dot)edu> writes:
>>>> Am I right in thinking that UNION (without ALL) is defined to do a
>>>> DISTINCT on its result, so that duplicates are removed even if the
>>>> duplicates both came from the same source table? That's what 6.4.2
>>>> does, but I do not know if it's strictly kosher according to the SQL
>>>> spec.
> (Just in case this is still active)
> Yes, this is the right behavior according to SQL92...
OK, then 6.5 is still broken :-(. I know a lot more about the planner
than I did then, so I will see if I can fix it "right" --- that is,
without taking out equal()'s ability to detect equality of Query nodes.
If that seems too hard/risky, I will just lobotomize equal() instead.
Thanks for the reminder, Bruce --- I had forgotten about this issue.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 1999-05-09 17:40:05 | Re: [HACKERS] Re: Number of parameters in a sql function |
Previous Message | Tom Lane | 1999-05-09 17:21:59 | Re: [HACKERS] ODMG interface |